Frozen shoulder (adhesive capsulitis): embolization for stubborn pain

What frozen shoulder is

In adhesive capsulitis, the capsule around the shoulder joint becomes inflamed and thickened, and the shoulder gradually stiffens. It typically moves through a painful phase, a stiff (frozen) phase and a thawing phase, and can take one to two years or longer. It is more common in people aged 40 to 60, in women, and in people with diabetes or thyroid disease. Pain at night and difficulty reaching behind the back or overhead are typical.

Usual treatment first

Treatment starts with physiotherapy, anti-inflammatory medicines and often an injection of steroid into the joint. If these do not help, options include hydrodilatation (stretching the capsule with fluid), manipulation under anaesthesia and arthroscopic capsular release. Embolization is considered for people whose pain remains severe after these steps, or who prefer to avoid surgery.

How embolization works

Imaging in frozen shoulder shows abnormal new blood vessels in the inflamed capsule, and nerve fibres grow with them. In embolization, a catheter is guided to the small arteries that supply these vessels, usually from the groin or wrist, and tiny particles or a temporary agent such as imipenem/cilastatin close them. The aim is to lower the inflammation and relieve pain, so that physiotherapy can restore movement ^{[1, 2]}.

How the procedure is done

The procedure is done as day-care and takes about 45 to 90 minutes.

• Your shoulder is examined, and an X-ray, ultrasound or MRI confirms the diagnosis and rules out other causes of shoulder pain. Kidney function is checked.
• Under local anaesthetic, a catheter enters an artery and is guided to the small arteries around the shoulder under X-ray.
• Contrast dye shows abnormal vessels, and the particles are injected until they disappear.
• The catheter is removed, and you go home the same day. Physiotherapy continues afterwards.

What the studies show

In the first larger series of 25 patients with frozen shoulder that had not improved with conservative treatment, average overall pain fell from 82 mm before the procedure to 52, 19 and 8 mm (on a 100 mm scale) at 1, 3 and 6 months, with no major complications. 67% had a major improvement in night pain within a week ^[1]. A mid-term study of 40 patients found pain fell from a median of 8 to 0.5 out of 10 at 6 months, with improved forward movement (79.5 to 133 degrees), no complications, and no recurrence at an average follow-up of 21 months ^[2]. A 2026 narrative review of 11 clinical studies and 422 patients found similar results, but noted different definitions of success, varied follow-up and no control groups ^[3].

A 2026 modelling analysis, using indirect comparisons rather than a head-to-head trial, estimated clinical success (mild pain at 3 months) of 73.3% with embolization, 61.4% with arthroscopic release and 55.5% with manipulation. When success meant recovery of range of motion, manipulation and release did better ^[4].

Options compared

The right option depends on whether pain or stiffness dominates, and how long you have had it.

Risks

Reported effects are bruising at the puncture site, temporary soreness or skin discolouration, and, rarely, closure of a non-target artery. No major complications were reported in the studies above, but they were small. Your doctor explains your individual risks before you consent ^{[1, 2, 3]}.

Cost and insurance

The cost depends on the procedure, the embolic material used and the day-care facility, and is explained after consultation and a review of your scans. Because these treatments are newer, insurance cover varies between policies and is checked before the procedure, and it is never assumed. Please ask the team for the specifics of your policy.